We should probably scratch that last one, as your custom Geofilter has to be submitted and approved by Snapchat. You'll set the borders of where you want you Geofilter to appear on a map using a "geofence." Then, you'll set the duration of your Geofilter, anywhere from 1 hour to 30 days.

The green area shows where your Geofilter will be active. Image via Snapchat

Pricing starts at $5 and goes up from there depending on the size of the Geofilter's reach and your desired time frame. You can head here to get started. You can use your preferred image editing software to create your design, but Snapchat also has a few templates that work in Adobe Photoshop and Illustrator.